Bt Generator Voltage Regulator - Westerbeke 8.0KW-60Hz Service Manual

BT GENERATOR VOLTAGE REGULATOR ADJUSTMENTS
Description
The voltage regulator is an advanced design which ensures
optimum AC generator performance.
It
is equipped with
complete protection circuitry to guard against operating
conditions that could be detrimental to the AC generator.
VOLTAGE REGULATOR
Volts
This potentiometer is used to adjust output voltage. At proper
engine operating speed the output voltage should be held at
±l% from a no-load condition to a full rated generator output
and from power factor 1.0 - 0.8 with engine drive speed
variations up to -6%. Prior to starting the engine, turn the
VOLT and STAB trimmers (using a mini phillips screw-
driver) fully in a counter clockwise (Minimum) direction
until you feel them hit their stops. Tum the AMP and
HERTZ trimmers completely clockwise (Maximum) in the
same manner.
With
the generator running at no-load, at
normal speed, and with VOLT adjust at minimum, it is
possible that output voltage will oscillate. Slowly rotate the
VOLT adjust clockwise. The voltage output will increase and
stabilize. Increase the voltage to the desired value. In this
situation, only the green LED will stay lit.
Stability
'This potentiometer permits variation of the regulator's
response to generator load changes so as to limit overcom-
pensation and obtain a minimum recovery time to the normal
voltage output.
In order to adjust the regulator stability the generator must be
running at no-load and the output must be monitored.
Tum the STAB adjust slowly clockwise until the voltage
starts to fluctuate. At this point rotate the STAB adjust coun-
terclockwise until the voltage is stable within 1 or 2 tenths of
a volt.
Hertz
Amp
Stab
Volt
VOLTAGE REGULATOR DIAGRAM
Amp-Hertz
These two adjustments are used in conjunction with the two
protection circuits in the voltage regulator that are indicated
by the illumination of colored LED lights.
1.
Delayed overload protection (yellow LED).
2. Low speed protection (red LED).
Both systems have an intervention threshold which can be
adjusted using the respective potentiometer. Each of the two
circuits are able to cause an adequate reduction in excitor
voltage to safeguard the excitor windings and prevent their
overheating.
The overload protection system has a delay which permits
temporary overloading of the generator during times such as
motor start-up or other similar load surge demands. The regu-
lator also has a third LED (green), that glows during genera-
tor operation to indicate correct operation of the regulator
with the generator.
Setting the Overload Protection
In order to set the AMP overload protection, the generator
must be loaded to its full output rating.
1. Load the generator to its rating, then decrease the speed of
the engine by 10.10% (54 Hertz on 60 hertz units, 45
hertz on 50 hertz units).
2. Rotate the AMP adjustment counterclockwise until it hits
its stop. Wait about 15-20 seconds after which the AC out-
put of the generator should drop and the yellow LED light
should come on.
3. Slowly rotate the AMP adjustment clockwise until the
output voltage increases to approximately 97% of the volt-
age output at the start of the adjustment. At this point the
yellow LED light should come on.
4. Return to nominal speed, the yellow LED will turn off
and the generator voltage will rise to
its
normal value.
Should this not happen, repeat the adjustment.
NOTE:
When changing from
60
hertz to
50
hertz operation,
remove the
60
hertz jumper bar from the regulator board.
Setting the Underspeed Protection
NOTE:
If the unit is operating at
60
Hertz ensure that the
jumper strap is in place on the regulator board between the
two
60
Hertz terminals. In order to adjust the underspeed
setting, the generator should be running at no-load.
1.
To adjust the underspeed (low frequency) protection circuit,
lower the engine speed at 90% of its normal running speed
(54 hertz on 60 hertz units, 45 hertz on 50 hertz units.
2. Rotate the Hertz adjustment counterclockwise slowly until
the generator's AC output voltage starts to decrease and at
the same time the red "LED" light comes on.
3. Increase the engine speed to its nonnal speed (frequency).
The red "LED" light will go out and the AC voltage out-
put will return to nonnal.
With the above adjustments made, the regulator should func-
tion normally.
-.,.yo
WESTERBEKE
Engines & Generators
79